In many jurisdictions, the use and storage of hazardous or flammable chemicals is controlled by laws and regulations. For example, use and storage of flammable chemicals, such as flammable solvents and similar materials, is closely regulated. These laws and regulations also control what kind of buildings and workplaces a business entity may use to store and use the chemicals.
For example, the California Fire Code (CFC) and the California Building Code (CBC) impose such regulations. Under CBC, building facilities used by business entities are classified, among other classifications, as B-2, F, and H-2. Such classifications may apply to entire buildings or to selected control zones within a single facility. B-2 and F classifications are for general office and light industrial uses. H-2 is a hazardous facility classification. In general, a business entity occupying a B-2 or F facility faces far lower costs of occupancy and fewer regulatory controls than in an H-2 facility. Further, most jurisdictions provide zoning for H-2 facilities only in limited areas, whereas B-2 or F facilities are more widely allowed under zoning regulations.
CBC and CFC, Section 222-U, define such storage as either “Use Closed Systems” or “Use Open Systems.” Generally, a Use Closed System is one in which a vessel holding the hazardous chemical is closed or sealed continuously throughout use of the chemical, such that vapors emitted by the chemical are not liberated outside of the vessel or system and the chemical is not exposed to the atmosphere during normal operations. A Use Open System is one in which the vessel is continuously open in whole or in part during normal operations, such that vapors evaporating from the vessel are liberated may enter the building atmosphere.
A B-2 or F facility may have only limited quantities of chemicals that are defined as Use Open Systems; at present, the limit is a total of 30 gallons per control area in a facility, and each B-2 or F facility may have up to four (4) such control areas. However, the threshold for Use Closed Systems is much higher; at present, it is 120 gallons per control area. Above these threshold amounts, an expensive H-2 facility is required. Therefore, if a business entity needs to have more than 30 gallons of hazardous chemicals on hand for its operations, and the business entity is able to use only Use Closed Systems, it can successfully conduct its operations in a B-2 or F facility. If it only Use Open Systems are available, then the same entity would have to occupy an H-2 facility.
One context in which these regulations are important is the operation of high-pressure liquid chromatography (HPLC) equipment, which is widely used in biotechnology. Business entities that use HPLC equipment are often severely limited in the number of HPLC machines that they can operate within a B-2 or F control zone. While these entities would be more successful if they could operate more HPLC equipment, the entities do not wish to incur the costs of changing to an H-2 facility or control zone.
These issues also exist in jurisdictions other than California that are subject to the code of the National Fire Protection Agency (e.g., NFPA30) and the International Fire Code (IFC). The NFPA applies to the United States, Puerto Rico and the Virgin Islands; the IFC is in force in certain East Coast U.S. states, and the UFC is in force for certain West Coast states.
Accordingly, there is a need in this field for a way to conveniently, efficiently and inexpensively convert various chemical vessels from Use Open Systems to Use Closed Systems. Such a solution would allow certain business entities to have up to 120 gallons of Flammable-1B chemicals within each B-2 or F occupancy control area. In turn, such a solution would allow such entities to quadruple the quantity of chemicals that they can have within a B-2 or F occupancy, and to avoid building costly H-2 Hazardous occupancy building, which significantly increases construction cost.
A specific need in this context is to reduce the evaporation of chemicals from existing chemical vessels, bottles or other containers into the environment.
Still another related need is to provide a way to remove hazardous chemical vapors from the occupied environment and to direct them to an approved location, thus enhancing the environment and air quality within the occupied space.
Based on the foregoing, there is a clear need in this field for an apparatus for venting chemical vessels.
Useful approaches for addressing these issues are found in parent patent application Ser. No. 10/128,194, filed Apr. 22, 2002, now U.S. Pat. No. 6,672,194. In these approaches, evaporation control is provided in a vent header. It would be useful to have a way to control evaporation of vapors directly at the source, such as at a chemical bottle. Various forms of distributor caps for HPLC chemical bottles are known, such as Catalog No. D 606-08, D 607-08, and D 608-08 from Bohlender GmbH of Germany. These distributor caps provide a way to seal chemical distribution tubing to an HPLC bottle with a GL-45 threaded neck. However, there is no provision in the cap for preventing evaporation of vapors from the bottle. Thus, if a port in the cap is left open, or if tubing extending from a port in the cap is improperly routed, dangerous vapors can escape into the ambient environment. Accordingly, there is a need for a way to control evaporation at a chemical bottle.
The approaches described in this section could be pursued, but are not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.